A spatio-temporal long-term assessment on the ecological response of reef communities in a Caribbean marine protected area

Coral reef biodiversity is rapidly decreasing as a result of the loss of coral cover, which modifies the structure and functioning of the ecosystem. Understanding how coral reef communities respond in space and over the long term is essential in order to implement management strategies and reduce the effects of biodiversity loss on coral reefs. Fish, coral, and algae communities were used as indicators to evaluate changes in coral reef systems. The variation of these communities was studied in a marine protected area composed of three management zones in Cozumel Coral Reef National Park in Quintana Roo, Mexico, over a period of 11 years (2004-2014). The following parameters were monitored annually: (i) total fish density; (ii) fish trophic group densities; (iii) species richness and three fish diversity indices; (iv) relative scleractinian coral cover; and (v) relative macroalgae cover. In the years in which coastal development, such as the construction of a marina, took place, an increase in the abundance of territorial herbivorous and planktivorous fish was observed. As the coral recovered, macrocarnivores and sessile benthic invertivores were re-established, whereas scraper herbivores showed no changes in the period of study in any of the three management zones. Coral cover recovery showed rapid phase-shift reversal (phase-shift, macroalgae dominance over coral) in the three zones. Even though the fish density and coral cover recovered, the diversity indices of each fish trophic group exhibited a reduction in the three management zones over time.